lib/frratomic.h

   1 /*
   2  * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifndef _FRRATOMIC_H
  18 #define _FRRATOMIC_H
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #ifndef FRR_AUTOCONF_ATOMIC
  25 #error autoconf checks for atomic functions were not properly run
  26 #endif
  27
  28 /* ISO C11 */
  29 #ifdef HAVE_STDATOMIC_H
  30 #include <stdatomic.h>
  31
  32 /* These are available in gcc, but not in stdatomic */
  33 #define atomic_add_fetch_explicit __atomic_add_fetch
  34 #define atomic_sub_fetch_explicit __atomic_sub_fetch
  35 #define atomic_and_fetch_explicit __atomic_and_fetch
  36 #define atomic_or_fetch_explicit __atomic_or_fetch
  37
  38 /* gcc 4.7 and newer */
  39 #elif defined(HAVE___ATOMIC)
  40
  41 #define _Atomic volatile
  42
  43 #define memory_order_relaxed __ATOMIC_RELAXED
  44 #define memory_order_consume __ATOMIC_CONSUME
  45 #define memory_order_acquire __ATOMIC_ACQUIRE
  46 #define memory_order_release __ATOMIC_RELEASE
  47 #define memory_order_acq_rel __ATOMIC_ACQ_REL
  48 #define memory_order_seq_cst __ATOMIC_SEQ_CST
  49
  50 #define atomic_load_explicit __atomic_load_n
  51 #define atomic_store_explicit __atomic_store_n
  52 #define atomic_exchange_explicit __atomic_exchange_n
  53 #define atomic_fetch_add_explicit __atomic_fetch_add
  54 #define atomic_fetch_sub_explicit __atomic_fetch_sub
  55 #define atomic_fetch_and_explicit __atomic_fetch_and
  56 #define atomic_fetch_or_explicit __atomic_fetch_or
  57
  58 #define atomic_add_fetch_explicit __atomic_add_fetch
  59 #define atomic_sub_fetch_explicit __atomic_sub_fetch
  60 #define atomic_and_fetch_explicit __atomic_and_fetch
  61 #define atomic_or_fetch_explicit __atomic_or_fetch
  62
  63 #define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
  64                                               mem2)                            \
  65         __atomic_compare_exchange_n(atom, expect, desire, 1, mem1, mem2)
  66
  67 /* gcc 4.1 and newer,
  68  * clang 3.3 (possibly older)
  69  *
  70  * __sync_swap isn't in gcc's documentation, but clang has it
  71  *
  72  * note __sync_synchronize()
  73  */
  74 #elif defined(HAVE___SYNC)
  75
  76 #define _Atomic volatile
  77
  78 #define memory_order_relaxed 0
  79 #define memory_order_consume 0
  80 #define memory_order_acquire 0
  81 #define memory_order_release 0
  82 #define memory_order_acq_rel 0
  83 #define memory_order_seq_cst 0
  84
  85 #define atomic_load_explicit(ptr, mem)                                         \
  86         ({                                                                     \
  87                 __sync_synchronize();                                          \
  88                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0);            \
  89                 __sync_synchronize();                                          \
  90                 rval;                                                          \
  91         })
  92 #define atomic_store_explicit(ptr, val, mem)                                   \
  93         ({                                                                     \
  94                 __sync_synchronize();                                          \
  95                 *(ptr) = (val);                                                \
  96                 __sync_synchronize();                                          \
  97                 (void)0;                                                       \
  98         })
  99 #ifdef HAVE___SYNC_SWAP
 100 #define atomic_exchange_explicit(ptr, val, mem)                                \
 101         ({                                                                     \
 102                 __sync_synchronize();                                          \
 103                 typeof(*ptr) rval = __sync_swap((ptr, val), 0);                \
 104                 __sync_synchronize();                                          \
 105                 rval;                                                          \
 106         })
 107 #else /* !HAVE___SYNC_SWAP */
 108 #define atomic_exchange_explicit(ptr, val, mem)                                \
 109         ({                                                                     \
 110                 typeof(ptr) _ptr = (ptr);                                      \
 111                 typeof(val) _val = (val);                                      \
 112                 __sync_synchronize();                                          \
 113                 typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0);       \
 114                 do {                                                           \
 115                         old1 = old2;                                           \
 116                         old2 = __sync_val_compare_and_swap(_ptr, old1, _val);  \
 117                 } while (old1 != old2);                                        \
 118                 __sync_synchronize();                                          \
 119                 old2;                                                          \
 120         })
 121 #endif /* !HAVE___SYNC_SWAP */
 122 #define atomic_fetch_add_explicit(ptr, val, mem)                               \
 123         ({                                                                     \
 124                 __sync_synchronize();                                          \
 125                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val));        \
 126                 __sync_synchronize();                                          \
 127                 rval;                                                          \
 128         })
 129 #define atomic_fetch_sub_explicit(ptr, val, mem)                               \
 130         ({                                                                     \
 131                 __sync_synchronize();                                          \
 132                 typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val));        \
 133                 __sync_synchronize();                                          \
 134                 rval;                                                          \
 135         })
 136
 137 #define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
 138                                               mem2)                            \
 139         ({                                                                     \
 140                 typeof(atom) _atom = (atom);                                   \
 141                 typeof(expect) _expect = (expect);                             \
 142                 typeof(desire) _desire = (desire);                             \
 143                 __sync_synchronize();                                          \
 144                 typeof(*atom) rval =                                           \
 145                         __sync_val_compare_and_swap(_atom, *_expect, _desire); \
 146                 __sync_synchronize();                                          \
 147                 bool ret = (rval == *_expect);                                 \
 148                 *_expect = rval;                                               \
 149                 ret;                                                           \
 150         })
 151
 152 #define atomic_fetch_and_explicit(ptr, val, mem)                               \
 153         ({                                                                     \
 154                 __sync_synchronize();                                          \
 155                 typeof(*ptr) rval = __sync_fetch_and_and(ptr, val);            \
 156                 __sync_synchronize();                                          \
 157                 rval;                                                          \
 158         })
 159 #define atomic_fetch_or_explicit(ptr, val, mem)                                \
 160         ({                                                                     \
 161                 __sync_synchronize();                                          \
 162                 typeof(*ptr) rval = __sync_fetch_and_or(ptr, val);             \
 163                 __sync_synchronize();                                          \
 164                 rval;                                                          \
 165         })
 166
 167 #define atomic_add_fetch_explicit(ptr, val, mem)                               \
 168         ({                                                                     \
 169                 __sync_synchronize();                                          \
 170                 typeof(*ptr) rval = __sync_add_and_fetch((ptr), (val));        \
 171                 __sync_synchronize();                                          \
 172                 rval;                                                          \
 173         })
 174 #define atomic_sub_fetch_explicit(ptr, val, mem)                               \
 175         ({                                                                     \
 176                 __sync_synchronize();                                          \
 177                 typeof(*ptr) rval = __sync_sub_and_fetch((ptr), (val));        \
 178                 __sync_synchronize();                                          \
 179                 rval;                                                          \
 180         })
 181
 182 #define atomic_and_fetch_explicit(ptr, val, mem)                               \
 183         ({                                                                     \
 184                 __sync_synchronize();                                          \
 185                 typeof(*ptr) rval = __sync_and_and_fetch(ptr, val);            \
 186                 __sync_synchronize();                                          \
 187                 rval;                                                          \
 188         })
 189 #define atomic_or_fetch_explicit(ptr, val, mem)                                \
 190         ({                                                                     \
 191                 __sync_synchronize();                                          \
 192                 typeof(*ptr) rval = __sync_or_and_fetch(ptr, val);             \
 193                 __sync_synchronize();                                          \
 194                 rval;                                                          \
 195         })
 196
 197 #else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
 198 #error no atomic functions...
 199 #endif
 200
 201 #endif /* _FRRATOMIC_H */